Thermal Treatment Influence on Selected Nutritional Values of Common Sea Buckthorn (Hyppophae rhamnoides) Juice

Since ancient times, sea buckthorn (Hyppophae rhamnoides) (SBT) has been utilized as a medical plant for its ability to extract health-promoting compounds from its fruits, seeds, pulp, skin, bark, roots, and leaves. L-ascorbic acid is primarily found in fruits, and because of this, it can be utilized as a fortification agent to enhance other juices. The study’s goal was to look into how the L-ascorbic acid and selected nutritional parameters in common sea buckthorn juice changed over the period of storage and different thermal treatments. The L-ascorbic acid stability in the processed juice in both used varieties (“Hergo” and “Leikora”) was ensured by the processing technology with a modified vat (or batch) (low-temperature long-time pasteurization) process. Even after being sterilized at 120 °C for 15 min, the amount of L-ascorbic acid in the processed sea buckthorn juice in both varieties was unaffected and ranged between 1762 and 2058 mg/kg. There was no change in the pH level at the same time; it stayed extremely low (about 2.3), which may have helped the L-ascorbic acid to stabilize. The sterilized juice variant in both varieties had the highest levels of glucose, fructose, total sugar, malic acid, total acid, and total soluble solids (TSS), which were significantly higher than in fresh juice or in either variant after pasteurization. Given this, we advise processing the SBT berries immediately after harvest using thermal processing to prevent ascorbic acid (AA) loss, or storing them under frost conditions until processing.